SH7713 Datasheet, PDF (234/904 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 5 Memory Management Unit (MMU)
31
10 9
0
VPN
Offset
Virtual Address (1-kbyte Page)
31
12 11
0
VPN
Offset
Virtual Address (4-kbyte Page)
(15)
(2)
(8) (1)
VPN (31-17) VPN (11-0) ASID V
(19)
PPN
(2) (1) (1) (1) (1)
PR SZ C D SH
TLB Entry
Legend
VPN: Virtual page number
Upper 22 bits of virtual address for a 1-kbyte page, or upper 20 bits of virtual address for a 4-kbyte
page. Since VPN bits 16 to 12 are used as the index number, they are not stored in the TLB entry.
Attention must be paid to the synonym problem (see section 5.4.4, Avoiding Synonym Problems).
ASID: Address space identifier
Indicates the process that can access a virtual page. In single virtual memory mode and user mode, or
in multiple virtual memory mode, if the SH bit is 0, the address is compared with the ASID in PTEH
when address comparison is performed.
SH: Share status bit
0: Page not shared between processes
1: Page shared between processes
SZ: Page-size bit
0: 1-kbyte page
1: 4-kbyte page
V: Valid bit
Indicates whether entry is valid.
0: Invalid
1: Valid
Cleared to 0 by a power-on reset. Not affected by a manual reset.
PPN: Physical page number
Upper 22 bits of physical address. PPN bits 11 to10 are not used in case of a 4-kbyte page.
PR: Protection key field
2-bit field encoded to define the access rights to the page.
00: Reading only is possible in privileged mode.
01: Reading/writing is possible in privileged mode.
10: Reading only is possible in privileged/user mode.
11: Reading/writing is possible in privileged/user mode.
C: Cacheable bit
Indicates whether the page is cacheable.
0: Non-cacheable
1: Cacheable
D: Dirty bit
Indicates whether the page has been written to.
0: Not written to
Figure 5.7 Virtual Address and TLB Structure
Rev.1.50 Aug. 30, 2006 Page 194 of 860
REJ09B0288-0150